Sorption of Cr(III) and Cr(VI) to K2Mn4O9 nanomaterial a study of the effect of pH, time, temperature and interferences

Authors

J. P. Valle, The University of Texas Rio Grande Valley
B. Gonzalez, The University of Texas Rio Grande Valley
J. Schulz, The University of Texas Rio Grande Valley
D. Salinas, The University of Texas Rio Grande Valley
U. Romero, The University of Texas Rio Grande Valley
Diego F. Gonzalez, The University of Texas Rio Grande Valley
Carolina Valdes, The University of Texas Rio Grande Valley
J. M. Cantu, The University of Texas Rio Grande Valley
Thomas Eubanks, The University of Texas Rio Grande Valley
Jason Parsons, The University of Texas Rio Grande ValleyFollow

Document Type

Article

Publication Date

7-2017

Abstract

A Rancieite type material (K2Mn4O9) nanomaterial was synthesized and tested for the removal of chromium (III) and chromium (VI) from aqueous solutions. The synthesized nanomaterial was characterized using powder XRD and SEM. XRD showed weak diffraction peaks at only at the angles associated with K2Mn4O9. The SEM corroborated that the nanoparticles were present; however, the nanoparticles were clustered into larger aggregates. Batch studies were performed to determine the optimum pH, capacity, time dependency, interferences, and the thermodynamics of the binding. The optimum pH for the binding of Cr(III) and Cr(VI) were determined to be pH 5 and pH 2, respectively. Isotherm studies were performed at temperatures of 4 °C, 25 °C, and 45 °C for Cr(III) and Cr(VI) and showed binding capacities of 21.7 mg/g, 36.5 mg/g, 41.8 mg/g for Cr(III). The Cr(VI) binding capacities were 4.22 mg/g, 4.08 mg/g, and 3.25 mg/g at the respective temperatures. The thermodynamic studies showed that the binding processes for the reactions were spontaneous and endothermic, with a ∆ H was 17.54 kJ/mol for Cr(III) and 6.05 kJ/mol for Cr(VI). The ∆ G of sorption for Cr(III) were determined to be − 3.88 kJ/mol, − 5.83 kJ/mol and − 7.03 kJ/mol at the aforementioned temperatures. The ΔG values for the Cr(VI) sorption were determined to be − 4.89 kJ/mol, − 5.64 kJ/mol, and − 6.05 kJ/mol. In addition, the ΔS values for Cr(III) and Cr(VI) were determined to be 77.92 J/mol and 39.49 J/mol, respectively. The thermodynamics indicate that the binding of Cr(III) and Cr(VI) is spontaneous and endothermic.

Comments

Original published version available at https://doi.org/10.1016/j.microc.2017.04.021

Recommended Citation

Valle, J. P., B. Gonzalez, J. Schulz, D. Salinas, U. Romero, D. F. Gonzalez, C. Valdes, J. M. Cantu, T. M. Eubanks, and J. G. Parsons. "Sorption of Cr (III) and Cr (VI) to K2Mn4O9 nanomaterial a study of the effect of pH, time, temperature and interferences." Microchemical Journal 133 (2017): 614-621. https://doi.org/10.1016/j.microc.2017.04.021

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.

Publication Title

Microchemical Journal

DOI

https://doi.org/10.1016/j.microc.2017.04.021